Hematopoietic consequences of gain-of-function SAMD9 and SAMD9L mutations

功能获得性 SAMD9 和 SAMD9L 突变的造血后果

• 批准号: 10363681
• 负责人: Jason Ross Schwartz
• 金额: $ 14.87万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-11-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10363681
• 关键词: ANXA5 gene; Addison' s disease; Advisory Committees; Alleles; Apoptosis; Architecture; Ataxia; Autophagocytosis; Award; Biological Models; Bone Marrow Diseases; CD34 gene; CRISPR/Cas technology; Caspase; Cell Count; Cell Cycle Arrest; Cell Line; Cell Proliferation; Cell Separation; Cells; Cellular Assay; Childhood; Chromosome 7; Chromosome Deletion; Chromosomes; Clinical; Clonal Evolution; Data; Development; Development Plans; Diagnosis; Disease; Dysmyelopoietic Syndromes; Educational workshop; Ensure; Evolution; Faculty; Flow Cytometry; Genes; Genetic; Genital; Genitalia; Genome engineering; Genomics; Germ-Line Mutation; Goals; Growth; Hematologic Neoplasms; Hematopoietic; Hematopoietic stem cells; Hypocellular Bone Marrow; In Vitro; Infection; Institution; Interferon-alpha; Interferons; K-Series Research Career Programs; Lead; Lesion; Location; Malignant Neoplasms; Maps; Mentors; Modeling; Molecular; Monosomy 7; Mutate; Mutation; Myelogenous; Myeloid Cells; Myelopoiesis; Myeloproliferative disease; Neoplasms; Nucleotides; Outcome; Output; Pancytopenia; Pathogenesis; Pathologic; Pathway interactions; Patients; Pediatric Hematology; Phenotype; Physicians; Prognosis; Proteins; Publishing; Recovery; Reporting; Research; Research Support; Resolution; Resource Sharing; Saint Jude Children' s Research Hospital; Sampling; Scientist; Series; Somatic Mutation; Stains; Syndrome; Time; Uniparental Disomy; Variant; alanine aminopeptidase; career; career development; chromosome 7 loss; clinical phenotype; cohort; cytotoxic; differential expression; experience; gain of function; gain of function mutation; genome sequencing; hematopoietic cell transplantation; improved; in vivo; induced pluripotent stem cell; insight; lectures; mutant; pediatric myelodysplastic syndrome; pressure; repaired; senescence; skills; stem cell model; stem cells; success; tool; transcriptome sequencing

PROJECT SUMMARY Heterozygous germline mutations in SAMD9 and SAMD9L have recently been described as a new class of MDS predisposing lesions and are present in approximately 10-20% of pediatric MDS cases. We and others have shown in published reports that MDS-associated germline mutations in SAMD9/9L increase the antiproliferative activity of the encoded protein and lead to hypocellular bone marrow with decreased myeloid cell numbers. In addition, we have shown that the development of a myeloid disease is associated with partial or full loss of chromosome 7 that results from the non-random loss of the pathologic mutation. Interestingly, somatic revertant mutations including in cis single nucleotide changes and conversion of the mutant allele to the wild-type through uniparental disomy occur in some cases which leads to hematopoietic recovery. Remarkably, some patients with monosomy 7, leading to a presumptive diagnosis of MDS, also achieve hematopoietic recovery through spontaneous disappearance of the monosomy 7 clone. These data lead to the hypothesis that gain-of- function (GoF) SAMD9/9L proteins are cytotoxic and cause strong selective pressure for cells lacking the mutant allele. The molecular mechanisms through which SAMD9/9L GoF mutations inhibit myelopoiesis, and the spectrum of secondary mutations leading to either MDS, MDS/AML (e.g. SETBP1), or spontaneous recovery is unknown. The proposed studies will investigate these questions through two specific aims: 1.) to determine the molecular and functional impact of mutant SAMD9 and SAMD9L expression during myeloid differentiation using and iPSC model system of pediatric MDS, and 2.) to determine the clonal architecture of cells expressing mutant SAMD9 and SAMD9L using serial patient samples and single cell genomics. A Mentored Clinical Scientist Research Career Development Award (K08) will provide the candidate with the amount of protected time needed to achieve his career goal of independence as a physician scientist and focus on improving the clinical outcomes of pediatric MDS patients through understanding the mechanisms of their disease pathogenesis. A strong career development plan including an experienced and successful faculty advisory committee, clear plans for progress assessments, and attendance at numerous courses, lectures, and workshops to increase proficiency in technical and management skills will accompany these research goals to ensure success as an independent physician scientist. This award will be completed at St. Jude Children’s Research Hospital (St. Jude), one of the world’s leading academic institutions focused on the research and treatment of pediatric catastrophic diseases, making it an exemplary location for an early career physician scientist to develop his career. In addition to the strong institutional support, St. Jude offers unmatched research support with facilities including the Genome Sequencing Facility at the Hartwell Center, a Flow Cytometry and Cell Sorting Shared Resource, and the Center for Advanced Genome Engineering (CAGE).

项目摘要 SAMD9和SAMD9L中的杂合种系突变最近被描述为新的MDS类 大约10-20％的小儿MDS病例中存在易感性病变。我们和其他人有 在已发表的报告中显示的是SAMD9/9L中与MDS相关的种系突变增加了抗增殖的 编码的蛋白质的活性并导致骨髓骨髓下降，并改善了髓样细胞数量。在 此外，我们已经表明，髓样疾病的发展与部分或全面损失有关 7染色体是由于病理突变的非随机丧失而导致的。有趣的是，体细胞恢复 突变包括在顺式单核苷酸中的变化和突变等位基因向野生型的转化 在某些情况下会导致造血恢复。值得注意的是，有些患者 单肌第7次，导致MDS的诊断，也可以通过 7克隆单肌的赞助消失。这些数据导致了以下假设 功能（GOF）SAMD9/9L蛋白是细胞毒性的，对缺乏细胞造成了强大的选择性压力 突变等位基因。 SAMD9/9L GOF突变抑制髓鞘的分子机制， 以及导致MDS，MDS/AML（例如SETBP1）或赞助的次级突变的光谱 恢复是未知的。拟议的研究将通过两个具体目的调查这些问题：1。）至 确定突变体SAMD9和SAMD9L表达过程中的分子和功能影响 使用小儿MD的IPSC模型系统的分化和2.）确定克隆体系结构 使用连环患者样品和单细胞基因组学表达突变体SAMD9和SAMD9L的细胞。 指导的临床科学家研究职业发展奖（K08）将为候选人提供 实现他作为物理科学家独立的职业目标所需的受保护时间数量 通过了解其机制，改善小儿MDS患者的临床结果 疾病发病机理。一项强大的职业发展计划，包括经验丰富且成功的教师 咨询委员会，进度评估的明确计划，以及参加众多课程，讲座和 提高技术和管理技能熟练程度的研讨会将处理这些研究目标 确保作为独立物理科学家的成功。该奖项将在圣裘德儿童教堂完成 研究医院（圣裘德）是全球领先的学术机构之一，专注于研究和 小儿灾难性疾病的治疗，使其成为早期职业医生的典范 科学家发展他的职业生涯。除了强大的机构支持外，圣裘德还提供无与伦比的研究 支持设施，包括Hartwell中心的基因组测序设施，流式细胞仪和 细胞分类共享资源和高级基因组工程中心（CAGE）。